其他发送的广播属于系统全局广播,其他应用可以获取到你发送的广播,或者其他应用可以给我们的广播接收器发送广播。本地广播的目的就是在于使发出的广播在应用程序的内部进行传递,而且本地广播的接收器也只能接收来自这个应用程序中的广播。
这个本地广播的示例是使用了动态注册,了解静态注册的可以看前两篇文章,首先创建一个本地广播接收器(和其他接收器无区别):
public class LocalBroadcastReceiver extends BroadcastReceiver {
@Override
public void onReceive(Context context, Intent intent) {
Toast.makeText(context, "received a local broadcast", Toast.LENGTH_SHORT).show();
}
}
之后我们在Activity中实现本地广播的收发:
public class LocalBroadcastActivity extends Activity {
private Button local_broadcast_btn;
private LocalBroadcastReceiver localBroadcastReceiver;
private LocalBroadcastManager localBroadcastManager;
private IntentFilter intentFilter;
@Override
protected void onCreate(@Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.local_broadcast_activity);
//使用localBroadcastManager来进行本地广播的控制
localBroadcastManager = LocalBroadcastManager.getInstance(this);
local_broadcast_btn = findViewById(R.id.local_broadcast_btn);
local_broadcast_btn.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Intent intent = new Intent("com.example.administrator.happyandroid.LOCALBROADCAST");
//使用localBroadcastManager进行发送广播
localBroadcastManager.sendBroadcast(intent);
}
});
intentFilter = new IntentFilter();
intentFilter.addAction("com.example.administrator.happyandroid.LOCALBROADCAST");
localBroadcastReceiver = new LocalBroadcastReceiver();
//使用localBroadcastManager注册广播接收器
localBroadcastManager.registerReceiver(localBroadcastReceiver, intentFilter);
}
@Override
protected void onDestroy() {
super.onDestroy();
localBroadcastManager.unregisterReceiver(localBroadcastReceiver);
}
}